scholarly journals Dietary l-Tryptophan Supplementation Enhances the Intestinal Mucosal Barrier Function in Weaned Piglets: Implication of Tryptophan-Metabolizing Microbiota

2018 ◽  
Vol 20 (1) ◽  
pp. 20 ◽  
Author(s):  
Haiwei Liang ◽  
Zhaolai Dai ◽  
Jiao Kou ◽  
Kaiji Sun ◽  
Jingqing Chen ◽  
...  
Keyword(s):  
Tight Junction ◽  
Mucosal Barrier ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Tight Junction Proteins ◽  
Weaned Piglets ◽  
Intestinal Mucosal Barrier ◽  
Mucosal Barrier Function ◽  
Small Intestinal ◽  
Junction Proteins

l-Tryptophan (Trp) is known to play an important role in the health of the large intestine. However, a role of dietary Trp in the small-intestinal mucosal barrier and microbiota remains poorly understood. The present study was conducted with weaned piglets to address this issue. Postweaning piglets were fed for 4 weeks a corn- and soybean meal-based diet supplemented with 0 (Control), 0.1, 0.2, or 0.4% Trp. The small-intestinal microbiota and serum amino acids were analyzed by bacterial 16S rRNA gene-based high-throughput sequencing methods and high-performance liquid chromatography, respectively. The mRNA levels for genes involved in host defense and the abundances of tight-junction proteins in jejunum and duodenum were measured by real time-PCR and Western blot techniques, respectively. The concentrations of Trp in the serum of Trp-supplemented piglets increased in a dose-dependent manner. Compared with the control group, dietary supplementation with 0.2–0.4% Trp reduced the abundances of Clostridium sensu stricto and Streptococcus in the jejunum, increased the abundances of Lactobacillus and Clostridium XI (two species of bacteria that can metabolize Trp) in the jejunum, and augmented the concentrations of secretory immunoglobulin A (sIgA) as well as mRNA levels for porcine β-defensins 2 and 3 in jejunal tissues. Moreover, dietary Trp supplementation activated the mammalian target of rapamycin signaling and increased the abundances of tight-junction proteins (zonula occludens (ZO)-1, ZO-3, and claudin-1) in jejunum and duodenum. We suggested that Trp-metabolizing bacteria in the small intestine of weaned pigs primarily mediated the beneficial effects of dietary Trp on its mucosal integrity, health, and function.

The Combined Effect of Vitamin C and Vitamin D3 on the Intestinal Epithelial Barrier by Regulating Notch Signaling Pathway

2019 ◽  
Author(s):  
Fubin Qiu ◽  
Zehui Zhang ◽  
Ying Ma ◽  
Linxue Yang ◽  
Rui Li
Keyword(s):  
Vitamin D ◽  
Vitamin C ◽  
Tight Junction ◽  
Mucosal Barrier ◽  
Control Group ◽  
High Dose ◽  
Tight Junction Proteins ◽  
Intestinal Mucosal Barrier ◽  
Notch Signal ◽  
Junction Proteins

Abstract Background: Tight junction proteins play crucial role in maintaining the intestinal mucosal barrier. Although previous studies had shown that the Notch signal is closely related to tight junction proteins, the mechanism by which it does so remains unknown. The goal of the present study was to investigate whether vitamin C combined with vitamin D3 affects intestinal mucosal barrier stability through Notch signal pathway.Results: To assess the effect of vitamin C combined with vitamin D3 on the intestinal mucosal barrier, electron microscopic observation of ultrastructure of tight junctions was done. And tight junction proteins gene and Notch signal gene expression were analyzed by quantitative reverse-transcription polymerase chain reaction, expression of tight junction protein in SW480 cells interfered with by LPS were examined by western blot. We found that vitamin C combined with vitamin D3 had protective effect on DSS-induced ulcerative colitis in guinea pig intestinal mucosa. Electron microscopy results showed that both low dose and high dose of vitamin C combined with vitamin D3 could maintain DSS-induced ulcerative colitis in guinea pig intestinal epithelium tight junction, however, the combination of medium dose vitamin C and vitamin D3 did not have this effect; Compared with the control group, the expression level of ZO-1 mRNA in the colon tissue of high-dose vitamin C group was significantly increased. In SW480 cell experiments, compared with the control group, the cell migration and repair ability of different concentrations of vitamin C combined with vitamin D3 group were significantly improved, the protein expression of Notch-1 was increased, but the protein expression of claudin-2 was significantly decreased. Conclusions: our results of this experiment showed that the appropriate amount of vitamin C combined with vitamin D3 might regulate the expression of claudin-2 by regulating Notch-1, slow the intestinal mucosal barrier destruction, and promote the damage repair of cell mucosal barrier.

scholarly journals Chitosan Ameliorates DSS-Induced Ulcerative Colitis Mice by Enhancing Intestinal Barrier Function and Improving Microflora

2019 ◽  
Vol 20 (22) ◽  
pp. 5751 ◽  
Author(s):  
Jia Wang ◽  
Cuili Zhang ◽  
Chunmei Guo ◽  
Xinli Li
Keyword(s):  
Barrier Function ◽  
Intestinal Microflora ◽  
Intestinal Barrier ◽  
Mucosal Barrier ◽  
Intestinal Barrier Function ◽  
Tight Junction Proteins ◽  
Intestinal Mucosal Barrier ◽  
Tnf Α ◽  
Mucosal Barrier Function ◽  
Junction Proteins

Ulcerative colitis (UC) has been identified as one of the inflammatory diseases. Intestinal mucosal barrier function and microflora play major roles in UC. Modified-chitosan products have been consumed as effective and safe drugs to treat UC. The present work aimed to investigate the effect of chitosan (CS) on intestinal microflora and intestinal barrier function in dextran sulfate sodium (DSS)-induced UC mice and to explore the underlying mechanisms. KM (Kunming) mice received water/CS (250, 150 mg/kg) for 5 days, and then received 3% DSS for 5 days to induce UC. Subsequently, CS (250, 150 mg/kg) was administered daily for 5 days. Clinical signs, body weight, colon length, and histological changes were recorded. Alterations of intestinal microflora were analyzed by PCR-DGGE, expressions of TNF-α and tight junction proteins were detected by Western blotting. CS showed a significant effect against UC by the increased body weight and colon length, decreased DAI (disease activity index) and histological injury scores, and alleviated histopathological changes. CS reduced the expression of TNF-α, promoted the expressions of tight junction proteins such as claudin-1, occludin, and ZO-1 to maintain the intestinal mucosal barrier function for attenuating UC in mice. Furthermore, Parabacteroides, Blautia, Lactobacillus, and Prevotella were dominant organisms in the intestinal tract. Blautia and Lactobacillus decreased with DSS treatment, but increased obviously with CS treatment. This is the first time that the effect of original CS against UC in mice has been reported and it is through promoting dominant intestinal microflora such as Blautia, mitigating intestinal microflora dysbiosis, and regulating the expressions of TNF-α, claudin-1, occludin, and ZO-1. CS can be developed as an effective food and health care product for the prevention and treatment of UC.

scholarly journals Sodium Butyrate Attenuates Diarrhea in Weaned Piglets and Promotes Tight Junction Protein Expression in Colon in a GPR109A-Dependent Manner

2018 ◽  
Vol 47 (4) ◽  
pp. 1617-1629 ◽  
Author(s):  
Wenqian Feng ◽  
Yancheng Wu ◽  
Guangxin Chen ◽  
Shoupeng Fu ◽  
Bai Li ◽  
...  
Keyword(s):  
Tight Junction ◽  
Signaling Pathway ◽  
Butyric Acid ◽  
Sodium Butyrate ◽  
Diet Group ◽  
Dependent Manner ◽  
Tight Junction Proteins ◽  
Weaned Piglets ◽  
Junction Protein ◽  
Junction Proteins

Background/Aims: Butyric acid plays an important role in maintaining intestinal health. Butyric acid has received special attention as a short-chain fatty acid, but its role in protecting the intestinal barrier is poorly characterized. Butyric acid not only provides energy for epithelial cells but also acts as a histone deacetylase inhibitor; it is also a natural ligand for G protein-coupled receptor 109A (GPR109A). A GPR109A analog was expressed in Sus scrofa and mediated the anti-inflammatory effects of beta-hydroxybutyric acid. This study investigated the effects of butyrate on growth performance, diarrhea symptoms, and tight junction protein levels in 21-day-old weaned piglets. We also studied the mechanism by which butyric acid regulates intestinal permeability. Methods: Twenty-four piglets that had been weaned at an age of 21 days were divided randomly into 2 equal groups: basal diet group and sodium butyrate + basal diet group. Diarrhea rate, growth performance during 3 weeks of feeding on these diets were observed, the lactulose-mannitol ratio in urine were detected by High Performance Liquid Chromatography, the expression levels of tight junction proteins in the intestinal tract and related signaling molecules, such as GPR109A and Akt, in the colon were examined by quantitative real-time PCR or western blot analyses on day 21. Caco-2 cells were used as a colon cell model and cultured with or without sodium butyrate to assess the expression of tight junction proteins and the activation of related signaling molecules. GPR109A-short hairpin RNA (shRNA) and specific antagonists of Akt and ERK1/2 were used as signaling pathway inhibitors to elucidate the mechanism by which butyric acid regulates the expression of tight junction proteins and the colonic epithelial barrier. Results: The sodium butyrate diet alleviated diarrhea symptoms and decreased intestinal permeability without affecting the growth of early weaned piglets. The expression levels of the tight junction proteins Claudin-3, Occludin, and zonula occludens 1 were up-regulated by sodium butyrate in the colon and Caco-2 cells. GPR109A knockdown using shRNA or blockade of the Akt signaling pathway in Caco-2 cells suppressed sodium butyrate-induced Claudin-3 expression. Conclusions: Sodium butyrate acts on the Akt signaling pathway to facilitate Claudin-3 expression in the colon in a GPR109A-dependent manner.

Digestion of epithelial tight junction proteins by the commensal Clostridium perfringens

2013 ◽  
Vol 305 (10) ◽  
pp. G740-G748 ◽  
Author(s):  
Mihaela Pruteanu ◽  
Fergus Shanahan
Keyword(s):  
Epithelial Cell ◽  
Tight Junction ◽  
Clostridium Perfringens ◽  
Culture Supernatant ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Tight Junction Proteins ◽  
Epithelial Tight Junction ◽  
Junction Proteins ◽  
E Cadherin

The enteric microbiota contributes to the pathogenesis of inflammatory bowel disease, but the pathways involved and bacterial participants may vary in different hosts. We previously reported that some components of the human commensal microbiota, particularly Clostridium perfringens ( C. perfringens), have the proteolytic capacity for host matrix degradation and reduce transepithelial resistance. Here, we examined the C. perfringens-derived proteolytic activity against epithelial tight junction proteins using human intestinal epithelial cell lines. We showed that the protein levels of E-cadherin, occludin, and junctional adhesion molecule 1 decrease in colonic cells treated with C. perfringens culture supernatant. E-cadherin ectodomain shedding in C. perfringens-stimulated intestinal epithelial cells was detected with antibodies against the extracellular domain of E-cadherin, and we demonstrate that this process occurs in a time- and dose-dependent manner. In addition, we showed that the filtered sterile culture supernatant of C. perfringens has no cytotoxic activity on the human intestinal cells at the concentrations used in this study. The direct cleavage of E-cadherin by the proteases from the C. perfringens culture supernatant was confirmed by C. perfringens supernatant-induced in vitro degradation of the human recombinant E-cadherin. We conclude that C. perfringens culture supernatant mediates digestion of epithelial cell junctional proteins, which is likely to enable access to the extracellular matrix components by the paracellular pathway.

scholarly journals Regulation of testicular tight junctions by gonadotrophins in the adult Djungarian hamster in vivo

Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 867-877 ◽  
Author(s):  
Gerard A Tarulli ◽  
Sarah J Meachem ◽  
Stefan Schlatt ◽  
Peter G Stanton
Keyword(s):  
Tight Junction ◽  
Adaptor Protein ◽  
Tight Junction Protein ◽  
Mrna Levels ◽  
Tight Junction Proteins ◽  
Djungarian Hamster ◽  
Junction Protein ◽  
Protein Localisation ◽  
Junction Proteins

This study aimed to assess the effect of gonadotrophin suppression and FSH replacement on testicular tight junction dynamics and blood–testis barrier (BTB) organisation in vivo, utilising the seasonal breeding Djungarian hamster. Confocal immunohistology was used to assess the cellular organisation of tight junction proteins and real-time PCR to quantify tight junction mRNA. The effect of tight junction protein organisation on the BTB permeability was also investigated using a biotin-linked tracer. Tight junction protein (claudin-3, junctional adhesion molecule (JAM)-A and occludin) localisation was present but disorganised after gonadotrophin suppression, while mRNA levels (claudin-11, claudin-3 and occludin) were significantly (two- to threefold) increased. By contrast, both protein localisation and mRNA levels for the adaptor protein zona occludens-1 decreased after gonadotrophin suppression. FSH replacement induced a rapid reorganisation of tight junction protein localisation. The functionality of the BTB (as inferred by biotin tracer permeation) was found to be strongly associated with the organisation and localisation of claudin-11. Surprisingly, JAM-A was also recognised on spermatogonia, suggesting an additional novel role for this protein in trans-epithelial migration of germ cells across the BTB. It is concluded that gonadotrophin regulation of tight junction proteins forming the BTB occurs primarily at the level of protein organisation and not gene transcription in this species, and that immunolocalisation of the organised tight junction protein claudin-11 correlates with BTB functionality.

scholarly journals Role of Tricellular Tight Junction Protein Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Cancer Cells

2019 ◽  
Vol 20 (14) ◽  
pp. 3555 ◽  
Author(s):  
Takayuki Kohno ◽  
Takumi Konno ◽  
Takashi Kojima
Keyword(s):  
Tight Junction ◽  
Cancer Progression ◽  
Epithelial Barrier ◽  
Dependent Manner ◽  
Tight Junction Proteins ◽  
Barrier Dysfunction ◽  
Endometrial Cells ◽  
Functional Changes ◽  
Junction Protein ◽  
Junction Proteins

Maintaining a robust epithelial barrier requires the accumulation of tight junction proteins, LSR/angulin-1 and tricellulin, at the tricellular contacts. Alterations in the localization of these proteins temporarily cause epithelial barrier dysfunction, which is closely associated with not only physiological differentiation but also cancer progression and metastasis. In normal human endometrial tissues, the endometrial cells undergo repeated proliferation and differentiation under physiological conditions. Recent observations have revealed that the localization and expression of LSR/angulin-1 and tricellulin are altered in a menstrual cycle-dependent manner. Moreover, it has been shown that endometrial cancer progression affects these alterations. This review highlights the differences in the localization and expression of tight junction proteins in normal endometrial cells and endometrial cancers and how they cause functional changes in cells.

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